1. Field of the Invention
The present invention relates generally to position monitoring/analysis of rotating machinery, and more particularly, to ease of accurately establishing mechanical angular position of rotating shafts.
2. Discussion of the Prior Art
Machinery that includes a rotating shaft may use a multi-event timing wheel to accurately establish mechanical angular position during shaft rotation. Often, requirements for a timing wheel are met for each installation by custom designing a wheel. The wheel must be fabricated with a precision inside diameter to fit a shaft diameter. The wheel is then split in half and clamped around the shaft. If the shaft diameter is incorrectly measured as too large or too small, the clamped design will not properly fit the shaft.
The process of splitting the timing wheel in half involves a saw which often leaves a kerf. The existence of the kerf allows over-tightening of the timing wheel which reduces the spacing of the kerf. This condition may result in an unequal spacing of the events in the wheel and subsequent error in the measured position. Alternatively, some machining of the timing wheel is done, the wheel is split in half, and then a spacer with the width of the kerf is added to the timing wheel so the rest of the machining can be completed. This adds complexity and cost to the manufacture of the timing wheel.
Timing wheels are often installed on the end of the rotating shaft. However, in many installations, the shaft ends are not accessible or the shaft ends are not suitable for installation of a timing wheel. As a result, an alternate location on the shaft must be selected. Frequently, the selected alternate location is an exposed location of the shaft adjacent to a bearing or rigid coupling. At times, an installation at these locations requires some amount of disassembly of the machinery to fasten the timing wheel to the shaft.
Accordingly, there is a need for a timing wheel apparatus for improving accuracy, minimizing production cost, and reducing disassembly of machinery during application of the timing wheel.